The invention relates to a method to protect underlying active features during a trench etch.
Electrical connection to devices may be provided by forming conductors above those devices. Conductors can be formed by subtractive or by additive (Damascene) means. In either case an etch is performed that will stop on or near the devices to be contacted.
During any etch, care must be taken to stop the etch at the desired point. Depending on the device, overetch may or may not be acceptable.
In devices in which overetch during a Damascene trench etch is harmful to the device, a method to prevent such harm is advantageous.